In recent years, there has been progress in the development of light-emitting devices using an organic EL element as a light-emitting unit. The organic EL element has a configuration interposing an organic layer between a first electrode and a second electrode. Such a light-emitting device may require transparency depending on its application. In order to make the light-emitting device transparent, the first electrode and the second electrode may be formed of a transparent conductive material.
On the other hand, in a case where the light-emitting device is made transparent, the edge of an electrode of an organic EL element may become conspicuous. In consideration thereof, Patent Document 1 discloses providing a correction layer in a region where no cathode is formed, the correction layer having the same material and thickness as those of the cathode. As an example of the cathode, a thin film of a metal such as magnesium, aluminum, or calcium having a low work function is disclosed. The correction layer is formed on the cathode with an insulating layer interposed therebetween.
Meanwhile, Patent Document 2 discloses a substrate provided with a transparent electrode, composed of a refractive index control layer and a transparent electrode layer formed in order on a transparent substrate. In Patent Document 2, the average refractive index of the refractive index control layer is 1.45 to 1.60. In addition, the refractive index control layer is formed as a laminate of two or more kinds of layers, the entire film thickness being 1,000 to 2,500 nm.